1. Field of Invention
The present invention relates to a wrench assembly.
2. Related Prior Art
U.S. Pat. No. 5,996,448 discloses a socket wrench including a handle 2, extension means 20 and a ratchet head 30. The extension means 20 includes receiving means 22 for receiving a shank 8 of the handle 2 and a shank 24 for insertion in receiving means 32 of the ratchet head 30. The shank 24 is equipped with a spring-loaded detent for abutting an internal face of the receiving means 32. The shank 8 is equipped with a spring-loaded detent for abutting an internal face of the receiving means 22. However, the detents cannot adequately retain the shank 24 within the receiving means 32 and the shank 8 within the receiving means 22. As compensation, the shanks 24 and 8 must be high enough and the receiving means 32 and 22 must be thick enough. Such large dimensions however make it difficult to use the wrench within limited space.
U.S. Pat. No. 5,996,448 discloses a socket wrench including a handle 2, extension means 20 and a ratchet head 30. The extension means 20 includes receiving means 22 for receiving a shank 8 of the handle 2 and a shank 24 for insertion in receiving means 32 of the ratchet head 30. The shank 24 is equipped with a spring-loaded detent for abutting an internal face of the receiving means 32. The shank 8 is equipped with a spring-loaded detent for abutting an internal face of the receiving means 22. However, the detents cannot adequately retain the shank 24 within the receiving means 32 and the shank 8 within the receiving means 22. As compensation, the shanks 24 and 8 must be high enough and the receiving means 32 and 22 must be thick enough. Such large dimensions however make it difficult to use the wrench within limited space.
U.S. Pat. No. 7,000,504 discloses a ratchet wrench 10 including tool members 40 selectively and changeably received in a compartment 13 thereof. The tool member 40 includes a peripheral groove 43 in which a resilient ring member 43 is adapted to locate. The ring member 43 is made of rubber or other synthetic materials so that it can be squeezed. A ratchet wheel 21 is mounted between the compartment 13 and the tool member 40 and includes an inclined surface 27 on an upper portion thereof. In coupling the tool member 40 to the ratchet wrench 10, the ring member 43 is inserted into a hole defined by the ratchet wheel 21 and is squeezed in order to pass through the hole. When the ring member 43 engages the inclined surface 27, the ring member 43 returns to its original cross sectional profiles and the tool member 40 is attached to the ratchet wrench 10. In disengaging the tool member 40 from the ratchet wrench, the process is reversed. While this attachment enables easy and quick engagement of the ratchet wrench 10 and the tool member 40, it nevertheless suffers from some problems. Firstly, since the peripheral groove 43 provides no redundant recessed space into which the ring member 43 is adapted to move during the engagement/disengagement of the tool member 40 and the ratchet wrench 10, the ring member 43 will rub against the ratchet wheel 21 and gradually wears out. Secondly, since the ring member 43 is made of rubber or other synthetic material and is not forced through the ratchet wheel 21 so as to be retained on the terminate edge of the ratchet wheel 21, it has poor efficacy to reinforce connection of the tool member 40 and the ratchet wrench 10. Thus the ring member 43 is easily accidentally disengaged with the inclined surface 27. Thirdly, the ring member 43 is adapted to return to its original shape and engage with the inclined surface 27 when the tool member 40 engages with the ratchet wrench 10. However, the tool member 40 gradually loses grip with the ratchet wrench 10 as the ring member 43 wears out.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.